let o = {age: 123, sex: 'female'};
let proxy = new Proxy(o, {
  get(target,key) {
    console.log("target:", target);
    console.log("key:", key);
    return Reflect.get(target,key)
  }
  , set(target,key,value) {
    // if(key === 'length') return true;
    console.log('update', key);
    return Reflect.set(target,key,value)
  }
});

const {sex} = o //不会触发 get
//输出nothing
